The present invention relates generally to plant irrigation devices and, in particular, pertains to an apparatus for the controlled irrigation of relatively large individual plants, such as shrubs and trees.
Due to ecological and cost considerations associated with the overusage of a limited water supply, it is desirable to water plants slowly thereby allowing water to soak into the ground around the plant, so as to provide the plant with sufficient water for growth and to maintain a high level of health, while minimizing or eliminating the wasting of water during such irrigation. In particular, if the plant is watered at too high a rate, not allowing time for the water to soak into the ground slowly, then the surface of the ground becomes supersaturated and the excess water will run off and be wasted. Furthermore, the excess water usage is reflected in higher utility bills.
Various irrigation systems have been previously used for years, as is shown in U.S. Pat. Nos. 3,199,791 and 3,482,785. The concept of providing a device for the watering of individual small plants was also demonstrated in U.S. Pat. No. 3,199,791 wherein a small leader hose projects from the main supply hose and extends individually to each plant and water is disbursed through one opening at the end of the leader hose. However, the '791 device was designed for small potted plants and not for trees or the like. Further, the water supply faucet in this device is located at the source of a feeding hose which is a substantial distance away, mounted on a side of a house or building, and this makes effective adjustment of the water flow inconvenient or very difficult, if the plant or leader hose outlet is not visible from the faucet.
As seen in U.S. Pat. No. 3,482,785, an improvement was made over the '791 patent wherein a valve was placed in the end of each leader arm so as to allow individual adjustment of the water flow to each individual plant. But the problem with this approach is that water is dispersed in only one particular location near the base of the plant, thereby leading to an uneven irrigation of the particular plant.
Consequently, an irrigation system is desired that provides an even distribution of water and covers a larger area around the base of the plant such that the entire root structure of the plant is watered evenly. Furthermore, a more convenient method of adjusting the water flow is necessary wherein the valve is not only located at or near the base of the tree or plant but includes at least one easy to locate position which will provide a known relatively low water flow rate. In addition, a system is needed which is adapted to effectively encircle a large plant and remain in a predetermined position relative to the plant during use and which is easily adjustable to the size of the plant and porosity of the ground.